From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A00C62D0636; Fri, 5 Sep 2025 09:02:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757062956; cv=none; b=Xg1kSogxzcxcRUt2vgygDZ1gFPPInPLlMAZ0LFGyz1gtMRNftmqu46yAYMF8VGqJAfRmlLq9hSz/Ft+ZkST1S1b1KKbaSAxDBahI6Q77O4Y3CsAKprahNUxDseSrG3ZbRPC/esgU+58u4fkMkOm6xh1yPNjtr8kZ2tP7n7PKpAU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757062956; c=relaxed/simple; bh=KT7TYlwSF7ukf4zSB0FdcwITV86mOnoX+raOv04H5Pg=; h=Subject:To:Cc:References:From:Message-ID:Date:MIME-Version: In-Reply-To:Content-Type; b=GPR7IAfnDoiPD0J5V6Ymte/kVCvrUfbfL3gix8+4Wdi+VoLnl9GjIXQEa12ZVLiYJ2x8WYqo5JWfNwKteC2DIZm061g6xTGQHPcM/DN9BJY3vF/UBBPgK8V93YiaJX7nMuWs7xyYk3HcLobMR9EJAieGCSaS8Vcr7+fgqYHQF3A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.216]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTPS id 4cJ9N74331zYQtJF; Fri, 5 Sep 2025 17:02:31 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 140161A1965; Fri, 5 Sep 2025 17:02:30 +0800 (CST) Received: from [10.174.179.143] (unknown [10.174.179.143]) by APP4 (Coremail) with SMTP id gCh0CgB3wY0lp7powuzYBQ--.44441S3; Fri, 05 Sep 2025 17:02:29 +0800 (CST) Subject: Re: [PATCH] md/md-linear: Enable atomic writes To: John Garry , song@kernel.org Cc: linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, martin.petersen@oracle.com, "yukuai (C)" References: <20250903161052.3326176-1-john.g.garry@oracle.com> From: Yu Kuai Message-ID: Date: Fri, 5 Sep 2025 17:02:28 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.1 Precedence: bulk X-Mailing-List: linux-raid@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <20250903161052.3326176-1-john.g.garry@oracle.com> Content-Type: text/plain; charset=gbk; format=flowed Content-Transfer-Encoding: 8bit X-CM-TRANSID:gCh0CgB3wY0lp7powuzYBQ--.44441S3 X-Coremail-Antispam: 1UD129KBjvJXoW7Aw4DZFWDAw1DCFy5Gr17Wrg_yoW8Gw4Dp3 yxXa4IyFyDJFyUWay5X3yxuF4Fgr98Jr47KFy3Xw40kFn5WrnrCFy3tws8XF9rAw1ru3Zr J3W0kryqv3Wqg3DanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUv0b4IE77IF4wAFF20E14v26r4j6ryUM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4 vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7Cj xVAFwI0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x 0267AKxVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG 6I80ewAv7VC0I7IYx2IY67AKxVWUGVWUXwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFV Cjc4AY6r1j6r4UM4x0Y48IcVAKI48JMxk0xIA0c2IEe2xFo4CEbIxvr21lc7CjxVAaw2AF wI0_JF0_Jw1l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4 xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r126r1D MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I 0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVW8 JVWxJwCI42IY6I8E87Iv6xkF7I0E14v26r4UJVWxJrUvcSsGvfC2KfnxnUUI43ZEXa7IUb iF4tUUUUU== X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ ÔÚ 2025/09/04 0:10, John Garry дµÀ: > All the infrastructure has already been plumbed to support this for > stacked devices, so just enable the request_queue limits features flag. > > A note about chunk sectors for linear arrays: > While it is possible to set a chunk sectors param for building a linear > array, this is for specifying the granularity at which data sectors from > the device are used. It is not the same as a stripe size, like for RAID0. > > As such, it is not appropriate to set chunk_sectors request queue limit to > the same value, as chunk_sectors request limit is a boundary for which > requests cannot straddle. > > However, request_queue limit max_hw_sectors is set to chunk sectors, which > almost has the same effect as setting chunk_sectors limit. > > Signed-off-by: John Garry > > diff --git a/drivers/md/md-linear.c b/drivers/md/md-linear.c > index 5d9b081153757..30ac29b990c9b 100644 > --- a/drivers/md/md-linear.c > +++ b/drivers/md/md-linear.c > @@ -74,6 +74,7 @@ static int linear_set_limits(struct mddev *mddev) > lim.max_hw_sectors = mddev->chunk_sectors; > lim.max_write_zeroes_sectors = mddev->chunk_sectors; > lim.io_min = mddev->chunk_sectors << 9; > + lim.features |= BLK_FEAT_ATOMIC_WRITES; > err = mddev_stack_rdev_limits(mddev, &lim, MDDEV_STACK_INTEGRITY); > if (err) > return err; > LGRM Reviewed-by: Yu Kuai